Gulf Shores, Ala. — Realty companies and hotels on Alabama's oil-stricken coast were hit with another wave of cancellations and lost business Tuesday after the free beachfront Jimmy Buffett concert was postponed because of the threat of Tropical Storm Alex.

With coastal tourism business already off by about half because of the huge BP oil spill in the Gulf of Mexico, promoters had planned the show for Thursday night in hopes of boosting crowds around the July Fourth holiday. The plan was to use a live concert telecast on CMT to show the state's beaches were open for business.

But phones at front desks and reservation offices began ringing almost immediately after organizers announced the show was being delayed until July 11. The delay was caused by the possibility that heavy surf from Alex could undermine the stage on the beach, creating a safety hazard. Some 35,000 free tickets already had been distributed.

Workers said they were swamped with calls at Meyer Real Estate, a major rental management company in the region, and two large hotels on the beach. Brett Robinson realty, with about 2,000 condominiums in the area, waived cancellation penalties for anyone who bought its concert package and didn't want to reschedule.

Kaiser Realty, another large company for beach rentals, said customers were either moving their reservations to July 11 or keeping them for the holiday weekend.

"We have had very few complete cancellations due to the concert change," said Emily Gonzalez, marketing director at Kaiser. The company offered a special that included two tickets to the show and a 25 percent discount on a condominium for the weekend.

Diane and Jerry McCreary decided they'd had enough of the coast after learning the concert was off. The couple, from Baldwyn, Miss., thought about extend their monthlong stay at an RV park but decided against it.

"We're going home tomorrow," said Diane McCreary, sitting in a chair on the nearly deserted public beach at Gulf Shores as tar balls rolled in with the surf. "Every day we have to move a little further away from the water because of the oil."

Buffett and music stars including Kenny Chesney and Zac Brown planned the free concert to help support a region struggling because of the BP PLC oil spill. Crude oil and tar balls have washed ashore at Gulf Shores and other Alabama beach resorts for weeks, hurting business during the summer tourist season.